16403909 has 4 divisors (see below), whose sum is σ = 16502304. Its totient is φ = 16305516.

The previous prime is 16403887. The next prime is 16403923. The reversal of 16403909 is 90930461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16403909 - 2¹⁶ = 16338373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16403939) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48947 + ... + 49280.

It is an arithmetic number, because the mean of its divisors is an integer number (4125576).

Almost surely, 2^16403909 is an apocalyptic number.

It is an amenable number.

16403909 is a deficient number, since it is larger than the sum of its proper divisors (98395).

16403909 is an equidigital number, since it uses as much as digits as its factorization.

16403909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98394.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 16403909 is about 4050.1739468818. The cubic root of 16403909 is about 254.0870028695.

The spelling of 16403909 in words is "sixteen million, four hundred three thousand, nine hundred nine".